Maltitol, one of sugar alcohols, is a low-calorie sweetener which exhibits sweet taste like sucrose and is used for various products. These days, the use of maltitol in coatings of tabletted chewing gum, pills and the like has been increasing.
In general, there are two types of methods to apply coatings. One is a hard coating method which comprises repeating the steps of coating a core material with a sugar solution and drying the coated core material. The other is a soft coating method which comprises repeating the steps of coating a core material with a sugar solution, further coating the core material with powders of the sugar and drying the coated core material. Currently, the hard coating method predominates.
Maltitol is also used for coating. The hard coating method which comprises repeating the steps of coating a core material with highly pure aqueous maltitol solution and drying the coated core material has been employed. This method can provide a smooth coating, but thus coated layer tends to be chipped during its processing and it takes a long time to complete the coating.
WO2003/000068 proposes to add a binder to the coating syrup. The use of binders seems to be effective in preventing the coating from being chipped but it is expensive. The coating procedure of the patent also takes a long time. In addition, hard coating method requires maltitol with high-purity.